My first ever DIY amp - 1981

[reubensm]

You brought back old memories of TBA810, LM381 etc. And the
infamous Delhi make cassette decks (Chawla mechanism etc). I
was so thrilled to get a hydraulic soft eject Japanese mechanism with
a glass ferrite head for my DIY casette player -
moved from a discrete pre to a LA3161, and amp was 2 * TBA810.
Even glass epoxy PCBs were such a rarity.

The 2N3055 based Philips 40W, or the STK amps
were too expensive for me.
Of course, I went through the obligatory bird bells, running LEDs,
misc 555 ckts, digital clock etc, AC128 based pocket radio and so on.
A huge discovery for me was TTL and CMOS (74xx and 4xxx)
series ICs.

I think Elecktor started the Indian edition in 1983?
I really lusted for the stuff in the UK editions and
the Elektor books (one on the micoprocessor kit and their
circuits collection, including a full TTL clock with alarm etc).

Fantastic...remember the Chawla mechanisms, saved all my pocket money to buy one for Rs.150 (think it was) but it was so unreliable. I've built amps with AD149, AD161/AD162 and even used the STK amps...all DIY

 

[reubensm]

Oh how can I forget those circuits assembled not on veroboards but on piece of cardboards! Those were the days. Now dont get enough time to devote, with the two small kids playing around in the house.

yes, i too remember building a medium wave transmitter on a piece of cardboard taken from a note book. Have even used the top of my school pencil box as a circuit board, had to solder whith great care to avoid getting the plastic to melt The project I built on the plastic lid of an OATS tin was a BC148b based cassette head preamp (1986)

great memories!!

 

[navin advani]

Great to see DIY in India.

My first DIYin the early 70s were non audio electronic projects my aunt used to bring from the US. A few years later I moved to audio with a chip (LM382-1879) based amp. I think it was 6W or 8W rms.

Philips used to make some lovely (for the day) drivers. I prefered the sound of the Philips paper cones to the poly cone from Bolton. Around 1976 I built a 3 way using a 8" (8065) 5" (5060) and 2" cone tweeters (one facing therear to give the speaker some air) . A few year later I built a 100L behemoth using 2 12" 12066 woofers, a new 8" (8066) and dome mids (0210) and tweeters (0163 and 0140 for the rear). The fun never stopped.

Wow what a nostalgia trip.

 

[anilva]

You brought back old memories of TBA810, LM381 etc. And the
infamous Delhi make cassette decks (Chawla mechanism etc). I
was so thrilled to get a hydraulic soft eject Japanese mechanism with
a glass ferrite head for my DIY casette player -
moved from a discrete pre to a LA3161, and amp was 2 * TBA810.
Even glass epoxy PCBs were such a rarity.

The 2N3055 based Philips 40W, or the STK amps
were too expensive for me.
Of course, I went through the obligatory bird bells, running LEDs,
misc 555 ckts, digital clock etc, AC128 based pocket radio and so on.
A huge discovery for me was TTL and CMOS (74xx and 4xxx)
series ICs.

I think Elecktor started the Indian edition in 1983?
I really lusted for the stuff in the UK editions and
the Elektor books (one on the micoprocessor kit and their
circuits collection, including a full TTL clock with alarm etc).

It is just so shockingly similar from the stories here. If you were in Hyderabad during those days, we might have crossed paths either in RLC electronics or Modern Electronics or Kiran Electronics.....or Jumierath Baazar....

 

[GeorgeO]

Story of many of our lives!


International travel, earnings and internet all came together much later to be able to pursue my hobbies with much more intensity.

Cheers.[/QUOTE]

Navin:

Greetings from Bangalore, and good to see you on this forum.

 

[captrajesh]

I dabbled in DIY stuff in a small way. I remember making a Crystal / Diode Radio and Disco LED lights. I still recollect the joy and delight of catching the faint sound of a local AM channel on the earphone that I connected. I have drawn the circuit of the disco LED lights that was published in the Electronics magazine so many times that I could draw it even sleeping for many years.

 

[quad]

It is just so shockingly similar from the stories here. If you were in Hyderabad during those days, we might have crossed paths either in RLC electronics or Modern Electronics or Kiran Electronics.....or Jumierath Baazar....

Indeed all the usual haunts - Modern, Kiran, Radio Center (Secbad/Koti),
Neelam Electronics, Integrated Electronics (in SecBad).
Modern is the only one which is pretty much unchanged (same
faces too, just a bit older ) - I recently got MJE15032/33
from them for the Marantz rebuild.
Rajesh Electronics opp to Modern stocks lot of parts now.
Kiran looks the same as in the 80s, but has far fewer parts now.

 

[navin advani]

Navin:
Greetings from Bangalore, and good to see you on this forum.

Hold it there. Your welcome tells me you know me from somewhere else. Is my past catching up with me?

I dabbled in DIY stuff in a small way. I remember making a Crystal / Diode Radio and Disco LED lights.

Talkng of LED lights....

IN the late 70s - I think it was 1979 or even 1980. I changed upon a LED circuit that was all the rage in Australia. In fact an Australina friend got me a head band of sorts that one could wear IN their hair that ran on a 9V battery.

Now in those days I had this big hair do (hey it was the Disco era) a la John McEnroe or Jimi Hendrix so I loved this LED thingy.

But it sparked my interest in all things LED. I bought dog collars and wired them with LEDs, wired LED circuits (and 555 timers) inside my t-shirts etc..

So one day I am walking down the street with LEDs in my hair and a wrist band made from a dog collar and a T-shirt brimming with LEDs and a senior man stops me and asks me how all of it is powered. ANd my response was the walking I do generates electrcity in my muscles and that electricity powers the LEDs. You should have seen his face. :lol:

 

[GeorgeO]

diyaudio via Akhil Lal

 

[SatSon]

Me too have some DIY memories. Started with an LED flashing circuit, a musical dancing circuit which didnt work properly:sad:,etc....
We had an old National Panasonic Ledsonic cassette deck receiver(with its own good 10" woofer big spk boxes)
the cassette deck mechanism of this was always having problems it being a soft-touch one with magnets used for lifting the head and pinch roller array. Finally I bought an Ellin(any one heard of it?) mechanism and made a seperate box for it. Removed the head and power(motor) from the receiver and gave it to the new box. Also tried Glass-metal head, seperate Head-pre etc in this. Had a good time with it for some time after which it also started showing frequent probs.
Last one was a 2N3055 based stereo amp for completing my 5.1 which was fed with a 12-0-12 5A transformer, one channel I used for powering my small 6" philips sub and the other one for the Center!
Sound was okay, but was not able to get the expected out of a 3055 from this.
The transformer was recently blown-off and so it is left unused now.

Now thinking of a mono 75-100W DIY amp for the above philips sub and any suggestions guys?

 

[quad]

IN the late 70s - I think it was 1979 or even 1980. I changed upon a LED circuit that was all the rage in Australia. In fact an Australina friend got me a head band of sorts that one could wear IN their hair that ran on a 9V battery.

So one day I am walking down the street with LEDs in my hair and a wrist band made from a dog collar and a T-shirt brimming with LEDs and a senior man stops me and asks me how all of it is powered. ANd my response was the walking I do generates electrcity in my muscles and that electricity powers the LEDs. You should have seen his face. :lol:

This is what a geek wears now....

You Built What?! A Wearable LED Television | Popular Science

 

[jls001]

Lots of rose-tinted nostalgia on this thread. My first venture into DIY was I think a 555-based circuit. I blew a capacitor due to wrong polarity. It was a good lesson as it taught me to be very careful with such components in all subsequent efforts. As it turned out, knowing how to read resistor values through DIY projects gave me quite an edge over classmates in engineering school when it came time to assemble myriad circuits in the electronics lab. In college, making a good electric guitar effects was my dream though I somehow never succeeded in making a good one that I actually liked. It's been so long that I've completely forgotten even how to read resistor values. My current build (WIP) of MyRef RevC is getting me back into electronics after so many years.

BTW, someone mentioned Koti in Hyderabad. I remember buying lots of different tape heads from that market (circa '92-93 I think). They used to put piles of them in baskets on the roadside, and I ended up picking quite a few good ones for cheap (starting at 20 rupees).

 

[reubensm]

This is what a geek wears now....

You Built What?! A Wearable LED Television | Popular Science

This is so funny, a similar incident happened with me and my little son. He has a pair of shoes that has built-in LEDs and squeaks when he walks. His class teacher asked my wife where we got the shoes from and about how it works. My wife apparently gave her some explaination about electricity generated by his feet :yahoo:

 

[reubensm]

Lots of rose-tinted nostalgia on this thread. My first venture into DIY was I think a 555-based circuit. I blew a capacitor due to wrong polarity. It was a good lesson as it taught me to be very careful with such components in all subsequent efforts. As it turned out, knowing how to read resistor values through DIY projects gave me quite an edge over classmates in engineering school when it came time to assemble myriad circuits in the electronics lab. In college, making a good electric guitar effects was my dream though I somehow never succeeded in making a good one that I actually liked. It's been so long that I've completely forgotten even how to read resistor values. My current build (WIP) of MyRef RevC is getting me back into electronics after so many years.

BTW, someone mentioned Koti in Hyderabad. I remember buying lots of different tape heads from that market (circa '92-93 I think). They used to put piles of them in baskets on the roadside, and I ended up picking quite a few good ones for cheap (starting at 20 rupees).

Cassette heads in baskets :lol:

Very interesting, I remember buying replacement cassette heads from similar sources in Trivandrum for between Rs.15 and 20, back in the late 80s, early 90s.